PROJECTSUMMARY/ABSTRACT Althoughcerebralvisualimpairment(CVI)istheleadingcauseoflowvisioninchildren,itisdifficulttodiagnose becauseaffectedchildrenoftenlacktheverbalandcognitiveskillsnecessarytoparticipateinstandard diagnosticprocedures.Diagnostictestsexistthatworkaroundtheneedforeffectivecommunication,butthey areeithersubjectiveorimpracticaltoadminister.Asaresult,CVIislikelyunderdiagnosed,andsincethereis noeffectivetreatment,mostpatientsfacealifetimeofdisability.Thisresearchprojectwillevaluatetheutilityof OptokineSys,anoveltoolwedevelopedformeasuringvisualfunctioninbraininjuredchildren.Thesystem automaticallydetectssmoothtrackingeyemovementsusing3mainelements:acomputerdisplayfor presentingvisualstimuli,adesktopeyetrackingdevice,andacomputeralgorithmtodeterminewhetherthe eyesaremovinginsynchronywiththevisualstimulus.Thesystemusesanautomatedprocedureto systematicallyadjustthespatialfrequency(finenessofdetail)orcontrast(lighttodarkratio),themost widelyusedmeasuresofspatialvisualfunction.Thesystemautomaticallyseeksthethresholdsetting?i.e.the mostchallengingstimulusatwhichthesubjectcontinuestotrack.Thesystemalsokeepschildrenengagedin thetaskbyprovidingrealtimerewardintheformofmusicthatisplayedonlywhentheyfollowthestimulus. SpecificAim1willcomparemeasuresmadewithOptokineSysagainststandardmeasuresofvision,inchildren withbraininjurywhocannonethelesscommunicate.OptokineSysmeasuresinthispopulationare hypothesizedtoretaincertaincharacteristicpropertiescomparedwithpsychophysicalmeasuresofspatial discriminationandcontrastsensitivity.Specifically,thiswillshowtheextenttowhichthenewsystems?results reflectvariationinthetargetpopulation?sspatialvisualfunction,asdesired,orareratherdominatedbyits variationinotherfunctionssuchasattentionandeyemovement.SpecificAim2willevaluatethereliabilityof OptokineSysinchildrenwhosebraininjuriespreventthemfromparticipatinginstandardvisualassessments. Forbothspatialfrequencyandcontrast,thresholdswillbetestedtwiceononedayandtwiceonthe subsequentday.Themainoutcomeisthetestretestreliability,asmeasuredbyvariability.Thevariabilityis hypothesizedtobehigherbetweendaysthanonthesameday,inkeepingwiththewaxingandwaningnature ofbrainfunctionfollowinginjury.Theseexperimentswilldeterminetheutilityofautomatedvision measurementsinanunderservedpopulationthatposesparticulardiagnosticchallenges.Thecurrentstudywill thuswilllaythegroundworkforfutureclinicaltrialsofOptokineSysasatoolforassessingthenaturalhistoryof CVIinchildrenwithbraininjury.Inaddition,thesystemcouldbeusedtotrainvisualperception,anapproach thathasalreadyprovedeffectiveinrodentstudies.Together,thenewsystemhasthepotentialtofillthegapin ourunderstandingofthecourseofCVIafterbraininjury,andtoprovidetoolsforchangingthatcourse.